1. Field of the Invention
This invention relates generally to the field of fabrics and other sheet materials used as window coverings particularly venetian type window coverings.
2. Description of the Prior Art
The window shade industry has developed many methods and apparatus for covering windows that provide privacy and thermal insulation while being aesthetically pleasing. Such window coverings should be capable of being raised and lowered as access to the window and other factors dictate. It would be advantageous to provide a venetian-type window covering that could, without being raised or lowered, be selectively placed in a closed position that provides privacy and insulation. The window covering should also be capable of being moved into an open position, allowing light to pass through the window covering. The opacity, color, and texture of the slats are primary ingredients to the overall appearance and effectiveness of the covering.
One attempt to provide such a window covering is disclosed in U.S. Pat. No. Re. 30,254 to Rasmussen. Rasmussen shows a honeycomb curtain structure that operates as a venetian-type window cover. Rasmussen accomplished this by forming a curtain structure from a series of foldable cells adhered together. Each cell has opposed side portions and a connected part. Thus, when the cells are connected, the top and bottom connected portions of each cell form the lamellae or slats of the venetian type structure. The features of the slat structure is limited by all the other requirements of the cell construction.
Another attempt to provide such a venetian-type window covering is disclosed in U.S. Pat. No. 3,384,591 to Froget. Froget shows a composite cloth which may be used as a blind. When the cloth is used as a blind, it is comprised of two transparent sheets connected by movable and opaque blades which are parallel to one another and are regularly separated and welded to the sheets. Welding or bonding the edges of these blades or slats is difficult to accomplish and the features of the slats are compromised to that end.
Colson in U.S. Pat. No. 5,490,553 and Moser in his German Patent No. DE 3525515 A1 show slats inserted into pockets formed by portions of the front and back layers. Although this allows for a different selection of materials for the slat than in Froget and Rasmussen, it is still limited by the necessity or difficulty of sliding a slat into a long narrow pocket. Further any texture or color of the slat is muted by the overlaying layer of pocket fabric.
In each of the above-referenced applications, there is difficulty or limitations in providing color, texture, flexibility, or opacity to the product with the slat. Froget and Rasmussen must make an entire layer for each quality, that is color, texture, or opacity of the slat. This is very expensive for the regional fabrication/distribution system in this country to inventory. Colson and Moser can use one multi-layer fabric assembly with many different slat colors and opacities, but the qualities of those slats are muted by the mesh of the surrounding pocket.
Another important feature is easy removal or replacement of the slat. This allows the consumer to readily clean the product or replace stained or faded slats. The consumer may even wish to change colors or patterns to match the season, a red for Christmas or a green for spring.